The California Department of Fish and Game voted Sept. 15 to close the fishery early but did not set a date.
The abalone season typically opens April 1, closes during the month of July and resumes between Aug. 1 and Nov. 30.
On Tuesday, the state's Office of Administrative Law approved the emergency regulations for an abalone closure effective 2:42 p.m. Tuesday.
The abalone season remains open along the coasts of Marin, Mendocino, Humboldt and Del Norte counties.
The die-off of abalone along the Sonoma Coast that started Aug. 27 coincided with a local red tide bloom and calm ocean conditions.
Although the exact reasons for the abalone deaths are not known, invertebrate die-offs have occurred in the past along the Northern California Coast due to lack of oxygen and/or poisoning when similar weather and bloom conditions existed, but not at the magnitude of the current event, the Department of Fish and Game said.
Dead abalone and other invertebrates were reported from Bodega Bay, Russian Gulch, Fort Ross, Timber Cove and Salt Point State Park in Sonoma County and as far north as Anchor Bay in Mendocino County.
Biologists and game wardens with the Department of Fish and Game continue to document reports of dead abalone and mussels and collect water samples, department spokesman Jordan Traverso said.
The public is encouraged to report the location, date and number of dead or dying abalone to Ian Taniguchi at (562) 342-7182 or by email to firstname.lastname@example.org.
Divers are encouraged to avoid the affected closed areas of the Sonoma Coast and are prohibited from taking abalone.
They also are encouraged to see a physician and report any sickness they may have in connection with contact with abalone to their local health department.